Pulse generator timing circuits

ABSTRACT

A detector provides a signal for switching on the power supply of a proximately positioned transmitter upon the detection of desired information. A signal representative of the desired information is transmitted and, at predetermined times thereafter, coded signature signals are produced for transmission, these latter signals being supplied by a code generator upon the receipt thereto of pulses from a one-shot and/or repetitive interval timer. The one-shot timer at a predetermined period of time after receipt of the switching signal provides a single pulse to the code generator. The repetitive interval timer provides recurring pulses to the code generator at predetermined intervals of time after receipt of the switching signal. The system consumes no power in the standby mode.

United 'S'tate s- 'Patent [72] Inventor Henry Naubereit Browns Mill, NJ.21 Appl. No. 812,937 22 Filed Apr. 2, 1969 [45] Patented May 18, 1971[73] Assignee The United States of America as represented by theSecretary of the Navy [54] PULSE GENERATOR TIMING CIRCUITS 5 Claims, 3Drawing Figs.

[5 2] US. Cl 307/293, 307/268, 307/287, 307/324 [51] Int. Cl H03k 17/28[50] Field of Search 307/287, 293, 324, 273, 268; 328/55, 129-131 [56]References Cited UNITED STATES PATENTS 3,073,971 l/1963 Daigle, Jr.307/293X 3,098,953 7/1963 Herr 307/293X Primary Examiner-Stanley D.Miller, Jr. Attorneys Edgar J. Brower and Henry Hansen ABSTRACT: Adetector provides a signal for switching on the power supply of aproximately positioned transmitter upon the detection of desiredinformation. A signal representative of the desired information istransmitted and, at predetermined times thereafter, coded signaturesignals are produced for transmission, these latter signals beingsupplied by a code generator upon the receipt thereto of pulses from aone-shot and/or repetitive interval timer. The one-shot timer at apredetermined period of time after receipt of the switching signalprovides a single pulse to the code generator. The repetitive intervaltimer provides recurring pulses to the code generator at predeterminedintervals of time after receipt of the switching signal. The systemconsumes no power in the standby mode.

FROM

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HENRY NAUBEREIT A T TORNE Y PULSE GENERATOR TIMING CIRCUITSCROSS-REFERENCE TO RELATED APPLICATION This application is a division ofapplication Ser. No. 710,702 filed Feb. 27, 1968.

STATEMENT OF GOVERNMENT INTEREST The invention described herein may bemanufactured and used by or for the Government of the United States ofAmerica for governmental purposes without the payment of any royaltiesthereon or therefor.

BACKGROUND OF THE INVENTION The invention relates to timers and moreparticularly to timing networks that provide pulses at predeterminedintervals.

The present invention is contemplated for use as part of a device thatfunctions as an electronic spy to listen for and activate means fortransmitting signals indicative of vehicle and/or troop movements aswell as button bomb detonations, rifle fire, and the like. The devicemay be secreted behind enemy lines and, once so secreted, may beunrecoverable. Consequently, it-is paramount that transmission be keptat a minimum to both conserve power and avoid detection by the enemy. Itis also paramount that information, when transmitted, may reasonably beassumed to contain desired information rather than mere random-noise. Inaddition, as it is contemplated that a plurality of devices comprisingthe invention will be deployed in a predetermined pattern over a widearea, it is important that the listener know which one (or ones) of thedevices is transmitting.

SUMMARY OF THE INVENTION Accordingly, it is the general purpose of thisinvention to provide timing networks that supply pulses at predeterminedintervals.

In particular, one timing network provides a single pulse regardless ofthe length of time it is provided with a pair of input signals so longas the input signals exceed a predetermined period of time.

Another timing network provides a pulse at predetermined intervals solong as a pair ofinput signals continue.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a block diagram of the systemshowing the various elements thereof in accordance with the invention;

FIGS. 2 and 3, are schematic diagrams of certain of the block diagramelements of FIG. 1.

7 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingand more particularly to FIG. 1, there is shown an adaptive acousticdetector '10 in accordance with and more fully explained in patentapplication, Ser. No. 679,255, entitled, Adaptive Acoustic DetectorApparatus" by Henry Naubereit et al., filed Oct. 30, 1967, having at itsinput an acoustic sensor 11, which may be a microphone. A first outputfrom detector 10 is fed to a transmitter 16 through a mixer 17. Asdisclosed in the above-mentioned patent application, the detector 10provides a second output signal only when the signal received by sensor11 contains desired information, such as the sound of vehicle movement.Should no such second signal be provided, switch 14, positioned withinthe standby power control unit 15 and connected to the transmitter powersupply 18, is nonoperative. Thus, while the transmitter 16 continuouslyreceives information from detector 10 through mixer 17, the absence ofthe second signal from detector 10 prevents the closure of the switch 14and hence precludes the transmitter power supply 18 from supplying itsDC power to the transmitter 16. In this way, transmitter power isconserved, no power being consumed by the system in the standby mode.That is, power is consumed only upon the enabling of switch 14, acondition which occurs only upon the the receipt and detection ofdesired information by adaptive acoustic detector 10.

The switch 14, in addition to being electrically connected to thetransmitter power supply 18, is also electrically connected to twotiming elements, one one-shot timer 20 and a repetitive timer 21. Theoutputs of one-shot timer 20 and repetitive timer 21 are connected to acode generator 22 which, in response to signals received from the timers(in a manner hereinafter explained), provides a signal to mixer 17 andthence to transmitter 16. The mixer 17 is of the type that will passinformation from background insensitive amplifier 12 in the absence of acoded signature signal from code generator 22 and will pass the sum ofthe two signals in the presence of a coded signature signal. Both codedand uncoded information is radiated by antenna 23.

The operation of the system of FIG. 1 will be described. As I statedheretofore, if the detector 10 does not provide the second outputsignals, then even though detector 10 is providing the first signal totransmitter 16, the power supply 18 thereof is inoperative to supplypower due to the off condition of switch 14 and hence no signal isradiated by antenna 23. If, however, the detector 10 does supply thesecond signal, the switch 14 is rendered operative to thereby permit thepassage of voltage from transmitter power supply 18 to the transmitter16. Concurrently therewith, the supply 18 provides DC voltage to boththe one-shot timer 20 and the repetitive timer 21 through the electricalconnection 19. One-shot timer 20 is designed, as hereinafter disclosed,to provide a pulse 3.0 seconds after the closure, of switch 14. Thispulse is fed into the code generator 22 which, in response thereto,provides a coded signal to mixer 17. If the information (first signal)the adapted acoustic detector 10 persists for a period greater than 3seconds, the signature signal from code generator 22 mixes therewith inmixer 17 and the composite signal is supplied to transmitter 16 forradiation by antenna 23. Conversely, if the first signal from thedetector 10 persists for less than 3 seconds, the signature signal fromcode generator 22 will be passed by the mixer 17 directly to thetransmitter 16 for radiation thereby.

It is noted that regardless of the duration of the first signal fromdetector 10, or the duration of the second signal from the detector 10,the switch 14 remains operative, once so rendered, until it receives areset pulse via line 24 from repetitive timer 21. This will behereinafter described.

The transmitter power supply 18 also feeds the repetitive timer throughthe electrical conductor 19. Repetitive timer 21 is designed to providean output signal 10.0 seconds after the receipt of power from the supply18. The signal from repetitive timer 21 is fed concurrently to the codegenerator 22 and, via electrical conductor 24, back to switch 14. Thecode generator, in response to the signal received from the repetitivetimer 21, provides a signal to the mixer 17 in the same fashion asprovided upon receipt of a signal from one-shot timer 20. The signalfrom the code generator, 22, in response to the signal produced byrepetitive timer 21, is radiated by the antenna 23 either as part of acomposite signal or as merely the code signal itself in a manneridentical with the radiation of the signal from one-shot timer 20 andthe first output signal from detector 10.

The signature signal from code generator 22, in response to repetitivetimer 21, occurs 7.0 seconds after the signature signal responsive tothe signal supplied by one-shot timer 20. If, for example, a line oftroops passes by the sensor 11 in a period between 3.0 and 10.0 seconds,then the first signature signal from code generator 22 will mix with thefirst signal supplied by detector 10 and a composite signal will beradiated by antenna 23. The signature signal supplied as a result of thereceipt of a signal from repetitive timer 21, however, will not mix inthe mixer 17 and will instead be directly radiated by antenna 23. Inthis way the listener knows not only which of the strategicallypositioned devices is transmitting (as identified by the particular codesignal transmitted) but also the length of time, within rather narrowlimits, that a desired target is within the range of the sensor 11.

Once the switch 14 is closed, the transmitter remains ON until the powersupply 18 is disconnected therefrom by the disabling of switch 14. Thereset pulse provided at second intervals by the repetitive timer 21 vialine 24 attempts to reset or disable the switch 14 once every 10seconds. However, the switch 14 is of a type such that it can not bereset in the presence of the second signal from the detector 10. Thus,as long as the sensor 11 of FIG. 1 is receiving a desired target signal,the transmitter 16 will remain ON. Upon the occurrence of the absence ofa desired signal at sensor 11, however, the transmitter 16 remains ONfor the conclusion of the 10 second cycle whereupon, the detector 10 nolonger providing a second signal to switch 14, the reset pulse from thetimer 21 is operative to disable the switch 14 and thereby disconnectthe power supply 18 from the transmitter 16.

It is noted that the switch 14 is provided with a time-delay circuit ofsufficient duration to insure that the signature signal from codegenerator 22 (as derived from repetitive timer 21) will be radiated bythe antenna 23 prior to the disabling of the switch 14 upon receipt of areset pulse.

Referring now to FIG. 2, the operation of the one-shot timer will bedescribed. The timer 20 comprises an NPN transistor 40 having an emitter41, a base 42 and a collector 43. The collector 43 is connected to thetransmitted power supply 18 through a resistor 44. The base 42 isconnected to the switch 14 (and hence to the power supply 18) through avariable resistor 45. The base 42 is also connected to ground through avariable capacitor 46. The emitter 41 is connected to the anode 47 of afour-layer diode device 48. The cathode 49 thereof is connected to aresistor 50 and a pulse-shaping network comprising diodes 51 and 52 andresistor 53. The output to the code generator 22 is taken at one side ofthe resistor 53.

In the standby mode, power from transmitter power supply 18 develops avoltage through resistor 44 and hence upon the collector 43 of thetransistor 40. However, the base 42 receives no signal and hence thetransistor 40 is quiescent. Upon the receipt of a signal from detectingcircuitry 13, however, switch 14 is rendered operative and power fromthe supply 18 flows through the switch 14 and charges the variablecapacitor 46 at a rate determined by the ohmic value of variableresistor 45. The values of the resistor 45 and the capacitor 46 arepreselected to provide a time delay 3.0 seconds before sufficientvoltage is developed across the capacitor 46 such that it will dischargethrough the base 42 of transistor 40. Upon capacitor 46 discharging, thetransistor 40 is rendered conductive and power is conducted through thecollector resistor 44 and the transistor itself to overcome thebreakdown voltage of four-layer diode 48. This results in a sharp,positive going impulse or spike developed across the resistor 50. Thisspike is shaped by the diodes 51 and 52 such that a relatively squarepulse is developed across resistor 53 which is then fed into the codegenerator 22 thereby initiating the code signature signal process.

It is noted that the ohmic value of the resistor 44 is selected toprovide a sustaining current for the four-layer diode 48 so that eventhough capacitor 46 may be continually charging and discharging atthree-second intervals, no further output pulse from the timer 20occurs. Thus, regardless of the duration of the signal received by thesensor 11 of H6. 1, the oneshot timer 20 provides but one pulse to thecode generator 22, this pulse being provided 3 seconds after theenabling of switch 14.

The operation of the repetitive timer 21 will now be described. Withreference to FIG. 3, there is shown an NPN transistor 54, similar totransistor 40 OF FIG. 2, having an emitter 55, a base 56 and a collector57. The collector is connected to the power supply 18 through a resistor58. The base 56 is connected to the switch 14 through a variableresistor 59 and a four-layer diode 60 having an anode 61 and a cathode62. The anode 61 is connected both to one side of a variable resistor 59and to a variable capacitor 63, the other side of the capacitor 63 beingconnected to ground. The cathode 62 is connected to the base 56 of thetransistor 54 and to ground through a resistor 63. The emitter 55 oftransistor 54 is connected to ground through a resistor 65 while thecollector 57 is connected to one side of a capacitor 66, the other sideof the capacitor 66 being connected both to a resistor 67 and therespective anode and cathode of two diodes 68 and 69. The combination ofelements comprising capacitor 66 and diodes 68 and 69 provide apulse-shaping function which in conjunction with the resistor 67provides a sufiiciently wide and shaped pulse for supplying the codegenerator 22 with a signal upon which it can trigger.

Transmitter power supply 18 supplies a DC voltage to the collector 57through the resistor 58. However, as no signal is applied to the base56, the transistor 54 is quiescent. In addition, this voltage is blockedby the capacitor 66. Accordingly, the repetitive timer 2! consumes nopower in this, the standby mode. Upon the receipt of the second signalfrom detector 10, however, switch 14 is rendered operative and voltagefrom the supply 18 is passed through the switch 14 to charge thevariable capacitor 63 at a rate determined by the resistance of variableresistor 59. The values of the resistor 59 and capacitor 63 arepreselected to provide a time delay of 10.0 seconds before the breakdownpotential of four-layer diode 60 is reached such that the latter elementwill conduct. Upon this potential being achieved, the capacitor 63discharges through the diode 60 and the resultant electrical signal isapplied to the base 56 and is operative to render the transistor 54conductive. Upon conduction, a pulsed voltage signal is supplied acrossthe capacitor 66 and the resistor 67, a voltage division being affectedat point 70. The portion of the signal across the capacitor 66 is pulseshaped by the diodes 68 and 69 to concurrently provide an output pulseto the switch 14 and the code generator 22.

It is noted that the variable transistor 59 is selected to be largeenough to limit the current through the four-layer diode 60 such thatthat current is less than the required sustaining current for thedevice. Accordingly, the diode 60 is able to reset for another cycle,the cycle time being dependent upon the values of the resistor 59 andthe capacitor 63. Thus the repetitive timer 21 supplies a signal to thecode generator 22 and a reset signal to the switch 14 at 10 secondintervals. The switch 14 is not disabled, however, so long as a signalis present. Upon the occurrence of the absence of such a signal, thereset pulse is operative to open the switch 14 and thereby disengagesthe transmitter 16 from its power supply 18.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. lt is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

lclaim:

1. An electrical timer which consumes no power in the standby mode andwhich provides but one output pulse comprising:

time delay means adapted to provide an electrical signal a predeterminedtime after the receipt thereby of a first input electrical signal;

pulsing means connected with and responsive to said time delay means forproviding an output pulse including, a four-layer diode, and atransistor having its base connected to said time delay means and itsemitter connected to one side of said four-layer diode, said transistorbeing rendered conductive upon the receipt of said electrical signalfrom said time delay means;

a first resistor connected between ground and the other side ofsaidfour-layer diode; and

a pulse-shaping network connected across said first resistor.

2. An electrical timer according to claim 1 further including:

a second resistor for receiving a second input signal at one end thereofand connected at the other end thereof to the collector of saidtransistor, the ohmic value of said resistor being of sufficientmagnitude to provide a sustaining current through said four-layer diodesuch that said four-layer diode cannot reset.

3. An electrical timer which consumes no power in the standby mode andwhich provides an output pulse repetitively at predetermined intervalscomprising:

time delay means including a variable resistor and a variable capacitorconnected between one terminal of said variable resistor and ground forreceiving a first input electrical signal and for providing an outputelectrical signal in response thereto at the one terminal thereof apredetermined time after the receipt of said input signal;

pulsing means connected with said time delay means and responsive to theoutput electrical signal thereof for providing a pulse at predeterminedintervals including, a transistor and a four-layer diode one end of saiddiode being connected to the base of said transistor and the other endof said diode being connected to said electrical timedclay means at saidone terminal of said variable resistor;

a first resistor for receiving a second input signal at one end thereofand connected at the other end thereof to the collector of saidtransistor;

a capacitor connected at one end thereof to the collector of saidtransistor; and

a second resistor connected between ground and the other end of saidcapacitor, whereby said transistor is rendered conductive upon thedischarge of current through said four-layer diode.

4. An electrical timer according to claim 3 further includfirst andsecond diodes, each of said diodes connected across said second resistorsuch that the polarity of said first diode is opposite from the polarityof said second diode.

5. An electrical timer according to claim 2 wherein:

said capacitor and said first and second diodes comprise a pulse-formingnetwork; and

said variable resistance has an ohmic value of sufficient magnitude tolimit the current through said foublayer diode thereby to permit saiddiode to reset.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 5,990 Dated y 1 Inventor(s) Henry Naubereit It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 6, line 14, "2" should read Signed and sealed this 2nd day ofNovember 1971.

(SEAL) Attest EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting OfficerActing Commissioner of Patents FORM pomso (msg) uscoMM-oc GUEIJti-Pfis)Q U S (JOVEHNHKNT PRINTING OFFILF P16 0 lbs I.

1. An electrical timer which consumes no power in the standby mode andwhich provides but one output pulse comprising: time delay means adaptedto provide an electrical signal a predetermined time after the receiptthereby of a first input electrical signal; pulsing means connected withand responsive to said time delay means for providing an output pulseincluding, a four-layer diode, and a transistor having its baseconnected to said time delay means and its emitter connected to one sideof said fourlayer diode, said transistor being rendered conductive uponthe receipt of said electrical signal from said time delay means; afirst resistor connected between ground and the other side of saidfour-layer diode; and a pulse-shaping network connected across saidfirst resistor.
 2. An electrical timer according to claim 1 furtherincluding: a second resistor for receiving a second input signal at oneend thereof and connected at the other end thereof to the collector ofsaid transistor, the ohmic value of said resistor being of sufficientmagnitude to provide a sustaining current through said four-layer diodesuch that said four-layer diode cannot reset.
 3. An electrical timerwhich consumes no power in the standby mode and which provides an outputpulse repetitively at predetermined intervals comprising: time delaymeans including a variable resistor and a variable capacitor connectedbetween one terminal of said variable resistor and ground for receivinga first input electrical signal and for providing an output electricalsignal in response thereto at the one terminal thereof a predeterminedtime after the receipt of said input signal; pulsing means connectedwith said time delay means and responsive to the output electricalsignal thereof for providing a pulse at predetermined intervalsincluding, a transistor and a four-layer diode one end of said diodebeing connected to the base of said transistor and the other end of saiddiode being connected to said electrical time delay means at said oneterminal of said variable resistor; a first resistor for receiving asecond input signal at one end thereof and connected at the other endthereof to the collector of said transistor; a capacitor connected atone end thereof to the collector of said transistor; and a secondresistor connected between ground and the other end of said capacitor,whereby said transistor is rendered conductive upon the discharge ofcurrent through said four-layer diode.
 4. An electrical timer accordingto claim 3 further including: first and second diodes, each of saiddiodes connected across said second resistor such that the polarity ofsaid first diode is opposite from the polarity of said second diode. 5.An electrical timer according to claim 2 wherein: said capacitor andsaid first and second diodes comprise a pulse-forming network; and saidvariable resistance has an ohmic value of sufficient magnitude to limitthe current through said four-layer diode thereby to permit said diodeto reset.